If your store has multi-currency enabled, 1-click upsell offers will only appear for orders made in your store's default currency. For instance, if your store's default currency is CAD and the order was placed in USD, the offer will not display.

This restriction is due to Shopify’s post-purchase limitations, which are explained further here. You can also review Shopify's documentation for additional details.

Thank you page offers are not subject to the same limitations as 1-click offers, making them an excellent alternative in this scenario. We recommend setting up upsells to capture orders that may not see 1-click offers due to these restrictions.